#nav {
  height: 84px;
  width: 100%;
  position: absolute;
  display: flex;
  top: 0;
  z-index: 1000;
  justify-content: center;
  align-items: center;
  min-width: 1200px;
  transition-property: all;
  transition-duration: 0.3s;
  transition-timing-function: ease-in;
  .nav-content {
    width: 1200px;
    display: flex;
    justify-content: space-between;
    align-items: center;

    a {
      font-size: 16px;
      font-family: MILanPro_MEDIUM, Microsoft YaHei;
      text-decoration: none;
      color: #fff;
      display: inline-block;
      margin-left: 48px;
      padding: 5px;
    }
  }
}

#nav.show {
  position: fixed;
  background-color: rgba(45, 45, 45, .9);

  .nav-content {
    transform: translateY(0);
    transition: transform 280ms ease, -webkit-transform 280ms ease;
  }
}